Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. Measured changes in oxCCO (see Sec. 2 for a full explanation of this term) following hypoxia-ischemia (HI) in a piglet model. Each data point represents the recovery fraction of the broadband NIRS oxCCO signal and the P31 MRS NTP/epp (a surrogate marker of ATP). The broadband oxCCO measurements show a strong association (Pearson correlation, r=0.82) with the P31 MRS metabolic measurements and provide a good indication of outcome (good outcome refers to piglets that survived for more than 24 h following HI). The figure has been produced from data presented by Bainbridge et al. 10 Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO

Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. Number of papers published per year on the subject of cerebral NIRS measurements of CCO. The data were taken from the PubMed results for “cytochrome oxidase infrared spectroscopy brain” (with the addition of the 1977 Jöbsis paper). There are a total of 223 papers split into categories based on the subject: adults—67 papers (green), neonates—36 papers (red), animals—98 papers (blue) and other—23 papers (purple, including reviews of the subject, in vitro work and computational simulations). Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO

Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. Schematic of cellular metabolism with the electron transport chain and CCO expanded. CCO is represented as complex IV. This diagram is limited to the carbohydrate metabolism (from glucose); fat metabolism, also aerobic, is ignored. Chromophores that are measured by NIRS are highlighted in yellow boxes. Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO

Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. The extinction spectra of the absorbing cytochromes in the electron transport chain in the visible and NIR. The hemoglobin species extinction spectra are included for reference (450 to 740 nm from Zijlstra et al. 27 and 740 to 915 nm from Mark Cope, 28 causing the discontinuity at 740 nm). (a) Displayed between 400 and 1000 nm, note that the cytochrome b spectra are plotted on a secondary axis and (b) zoomed into the NIR region of 700 to 900 nm. Oxidized and reduced spectra of cytochrome c (oxCyt c and redCyt c, respectively) measured by Chris Cooper at the University of Essex in the porcine heart. Oxidized and reduced spectra of CCO (oxCCO and redCCO) measured by John Moody at the University of Plymouth in the bovine heart. Oxidized and reduced spectra of cytochrome b (oxCyt b and redCyt b) measured by Mike Wilson at the University of Essex. All data taken from the UCL Biomedical Optics Research Laboratory (BORL) website in Ref. 29. Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO

Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. Specific extinction coefficients measured by Mark Cope. 28 The ox-redCCO spectra are not the same as the difference between the CCO spectra presented in Fig. 4. Data taken from the UCL BORL website in Ref. 29. Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO

Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. Chart of wavelengths used in NIRS systems from all clinical publications mentioned in this review. Systems are listed in chronological order from their first publication in this review and are separated into three- and four-wavelength combinations and broadband spectra. The suggested wavelengths determined by Arifler et al. are also shown in Ref. 62. Clinical papers using the wavelengths are Duke 3λ, 22,63,64 UCL 4λ, 65 Duke 4λ, 66–68 Keele 4λ, 60,69–71 NIRO 1000, 72–75 Keele 3λ, 76,77 NIRO 500, 78–85 NIRO 300, 86–93 Critikon 2020, 94 UCLn, 7,41,58,95,96 Humboldt A, 33,97 Humboldt B, 98,99 and UCL Hybrid. 12,13,59,100,101 Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO

Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. Example residual analysis of NIRS data from the neonatal study by Bale et al. 96 (a) SpO2 spontaneous decrease showing two time points, before and during hypoxia, from which the change in attenuation is calculated. (b) Concentration results from fitting change in attenuation spectra to two- (HHb and HbO2) and three- (HHb, HbO2, and ox-redCCO) component models. (c) Attenuation measured and attenuation fit back-calculated from two- and three-chromophore fits. (d) Residual differences between real attenuation and back-calculated attenuations, and the difference between them; note the shape of the difference between the residuals for the two- and three-chromophore fits is similar to the ox-redCCO spectra (also plotted for comparison on a separate scale). Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO

Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. Physiological stimuli and predicted NIRS-measured hemoglobin oxygenation and oxCCO changes based on findings from this review for the healthy adult brain. Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO

Date of download: 7/11/2016 Copyright © 2016 SPIE. All rights reserved. Images of block-averaged concentration changes over the occipital lobe from (a) HbO2, (b) HHb, and (c) oxCCO for one subject. Images are recorded during half-field checkerboard visual stimulation, demonstrating spatial distribution of responses. There is an increase in HbO2 and oxCCO on the contralateral hemisphere during activation and a decrease in HHb. There are spatial differences between the hemoglobin and oxCCO images as assessed by center of gravity analysis. This figure has been produced from data presented by Phan et al. 105 Figure Legend: From: From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase J. Biomed. Opt. 2016;21(9): doi: /1.JBO